The present invention relates to an RF (radio frequency) coil, RF magnetic field generating apparatus and magnetic resonance imaging method and apparatus, and more particularly to an RF coil and RF magnetic field generating apparatus that generates an RF magnetic field in a direction parallel to the coil loop surface, and a magnetic resonance imaging method and apparatus employing such an RF magnetic field generating apparatus.
A magnetic resonance imaging apparatus with a static magnetic field direction perpendicular to the body axis of a subject, commonly referred to as a vertical magnetic field-type magnetic resonance imaging apparatus, generates an open static magnetic field space, and hence employs as an RF coil for generating the RF magnetic field an RF coil having a loop surface parallel to the pole piece surface of a static magnetic field generating unit. The RF coil of this type generates the RF magnetic field in the direction parallel to the coil loop surface to form the RF magnetic field perpendicular to the static magnetic field direction. Such an RF coil is disclosed in U.S. Pat. No. 5,760,583 of the present applicant.
On the other hand, there is another type of an RF coil referred to as a quadrature RF coil, which consists of a combination of two RF coils, and can provide an RF magnetic field having an increased strength through vector composition of respective RF magnetic fields generated by the two RF coils or can reduce a drive power per coil to generate the RF magnetic field of a desired strength.